Reduced levels of specific autobiographical memories in schizophrenia

Autobiographical memory is intrinsically related to the self and personal identity. This study investigated whether both personal episodic memory and semantic memory are impaired in schizophrenia, a disease characterized by an abnormal personal identity. Personal episodic memory and personal semantic memory were investigated in 24 patients with schizophrenia and 24 normal subjects using an autobiographical fluency task and an autobiographical memory inquiry. Autobiographical memory scores and the proportion of specific memories were lower in patients with schizophrenia than in normal subjects. The deficit of personal episodic and semantic memory, as assessed by the autobiographical memory inquiry and the autobiographical fluency task, respectively, was most apparent after the onset of clinical symptoms. Schizophrenia is associated with an impairment of both personal episodic and semantic memory and with a reduction of specific autobiographical memories. Those impairments are consistent with the existence of an abnormal personal identity in patients with schizophrenia.     

Overgeneral autobiographical memory in Parkinson's disease

Autobiographical memory (AM) concerns the ability to remember past events from one's own life and consists of autobiographical knowledge (personal facts) and autobiographical incidents (personal events). The novelty of this research was to assess both personal factual and personal event AM in Parkinson's disease (PD) for specified lifetime periods. An autobiographical fluency task was used in which participants were asked to recall personal events and personal facts from five separate lifetime periods. Previous findings as well the brain regions affected in PD lead to the hypothesis that Parkinson's patients would recall less autobiographical memories especially for the most recent lifetime periods. Sixteen non-demented and non-depressed Parkinson's patients and sixteen age-education-matched controls participated. The results showed a temporal gradient for the recall of personal events in Parkinson's patients as they recalled fewer events for recent time periods. The PD group also had more difficulties in recalling autobiographical events rather than an autobiographical knowledge. The difficulty in recalling autobiographical events was characterized by overgenerality, with PD patients failing to generate specific episodic memories.     

Effectiveness of a specific cueing method for improving autobiographical memory recall in patients with schizophrenia

Autobiographical memory deficits in schizophrenia have a significant impact on patients' daily life. Our study was aimed at testing the effectiveness of a specific cueing (SC) method for improving autobiographical memory recall in patients with schizophrenia, particularly the phenomenological details of their memories. Twenty-five patients with schizophrenia and 25 comparison participants took part in the study. They recalled 6 specific autobiographical events which occurred during 3 different life periods. After each memory recall, participants were given a general cue which allowed them to add further information to their narration. The SC was then applied by means of a series of specific questions to elicit more precise memory detail. The overall memory specificity as well as the number and richness of 5 categories of memory detail (perceptual/sensory, temporal, contextual, emotional, and cognitive) were assessed before and after the SC phase. Before SC, patients' memories were less specific and less detailed. SC had a beneficial effect on patients' memory recall. The overall memory specificity of patients improved. The gain in the number and richness of memory details was comparable between patients and comparison participants. The difference between groups in terms of the number of memory details was not significant. Richness of details was still lower in patients, except for emotional and cognitive details, which were similarly rich in both groups. The cueing method reduces the autobiographical memory impairment of patients with schizophrenia and paves the way for developing specific cognitive remediation therapies to help patients in their daily life.     

Long-term memory following transient global amnesia: an investigation of episodic and semantic memory

BACKGROUND: Several studies noted persistence of memory impairment following an episode of transient global amnesia (TGA) with standard tests. AIM: To specify long-term memory impairments in a group of patients selected with stringent criteria. METHODS: Both retrograde and anterograde memory were investigated in 32 patients 13-67 months after a TGA episode with original tasks encompassing retrograde semantic memory (academic, public and personal knowledge), retrograde episodic memory (autobiographical events) and anterograde episodic memory. RESULTS: Patients had preserved academic and public knowledge. Pathological scores were obtained in personal verbal fluency for the two most recent periods, and patients produced less autobiographical events than controls. However, when they were provided time to detail, memories were as episodic as in controls regardless of their remoteness. Anterograde episodic tasks revealed a mild but significant impairment of the capacity of re-living the condition of encoding, i.e. the moment at which words were presented. CONCLUSIONS: Patients who have suffered from an episode of TGA manifest deficits of memory focused on the retrieval of both recent semantic information and episodic memories and especially the capacity of re-living. These deficits may not result from a deterioration of memory per se but rather from difficulties in accessing memories.     

Episodic memory and self-awareness in Asperger Syndrome: Analysis of memory narratives

Previous findings from researchers on individuals with Asperger Syndrome (AS) suggest peculiarities of autobiographical memory (AM). They have shown a personal episodic memory deficit in the absence of a personal semantic memory impairment. The primary aim of this study was to explore AM in individuals with AS, and more specifically to investigate the link between episodic memory, self-awareness, and autonoetic consciousness through language analysis. We asked fifteen adults with AS and fifteen age- and IQ-matched controls to recall autobiographical memories from three life periods. Recorded interviews were processed using Alceste software. We found that participants with AS recalled fewer and less-detailed episodic memories than did controls. A content analysis revealed that family-related vocabulary as well as possessive pronouns was significantly less frequent in AS interviews than in those of controls. In conclusion, our results support the hypothesis that a deficiency of episodic memory may be due to poor awareness of the self in social relationships. Reduced use of possessive pronouns may also indicate less self-investment in life experiences, which would in turn impact recall.     

Patterns of autobiographical memory loss in dementia

BACKGROUND: Several studies have found impaired recall of remote autobiographical memories relative to recent memories in semantic dementia (SD), a pattern opposite to that in Alzheimer's disease (AD). OBJECTIVE: To document dissociation of memory for autobiographical incidents and personal semantic information in individuals with AD, frontotemporal dementia (FTD), and SD. METHODS: The authors administered the Autobiographical Memory Interview to eight individuals with AD, 11 with FTD, eight with SD, and eight normal controls . Autobiographical incidents and personal semantic memory was assessed from three time periods: childhood, early adulthood, and recent life. RESULTS: Individuals with SD recalled more details of autobiographical incidents from the most recent 5 years than from childhood and early adulthood (childhood vs recent life: t(7) = -3.59, p = 0.009; early adulthood vs recent life: t(7) = -4.33, p = 0.003). No difference was found between childhood and early adulthood (t(7) = 1.11, p = 0.305). Recall of personal semantic information was related to the age of the memory with less remembered from earlier time periods (childhood vs recent life: t(7) = -6.52, p < 0.001; childhood vs early adulthood: t(7) = -2.61, p = 0.035; early adulthood vs recent life: t(7) = -9.15, p < 0.001). CONCLUSIONS: SD is a compelling model in which to study the anatomy of episodic memory.     

Autobiographical memory and executive function in early dementia of Alzheimer type

We studied executive function and autobiographical memory in a cohort of 33 DAT patients [divided into minimal (MMSE 24–30) and mild (MMSE 17–23) groups] and in 30 normal controls. Autobiographical memory, as assessed by autobiographical fluency and the Autobiographical Memory Interview (AMI), was impaired in DAT patients, even those with minimal disease. There was evidence of a gentle temporal gradient on the incident but not the personal semantic component of the AMI, suggesting that the two components are dissociable. Executive function was assessed by two separate dual performance tasks and letter fluency. Although there was a trend for minimal DAT patients to be impaired on executive tasks, this only reached significance for the mild group. Regression analysis suggested that the divided attention component of working memory was involved in the retrieval of personal semantic autobiographical memory, but verbal fluency was more important in the retrieval of autobiographical incidents. There was thus a dissociation in the type of executive function implicated in different subcomponents of autobiographical memory, arguing for subcomponents within executive function and autobiographical memory. The autobiographical memory deficit in DAT reflects, we argue, both impairment in retrieval processes, linked to executive function, and a loss of memory stores.     

Autobiographical memory in semantic dementia: implication for theories of limbic-neocortical interaction in remote memory

We examined autobiographical memory performance in two patients with semantic dementia using a novel measure, the Autobiographical Interview [Levine, Svoboda, Hay, Winocur, & Moscovitch (2002). Aging and autobiographical memory: Dissociating episodic from semantic retrieval. Psychology and Aging, 17, 677-689], that is capable of dissociating episodic and personal semantic recall under varying levels of retrieval support. Earlier reports indicated that patients with semantic dementia demonstrate autobiographical episodic memory loss following a "reverse gradient" by which recent memories are preserved relative to remote memories. We found limited evidence for this pattern at conditions of low retrieval support. When structured probing was provided, patients' autobiographical memory performance was similar to that of controls. Retesting of one patient after 1 year indicated that retrieval support was insufficient to bolster performance following progressive prefrontal volume loss, as documented with quantified structural neuroimaging. These findings are discussed in relation to theories of limbic-neocortical interaction in autobiographical memory.     

Accuracy of episodic autobiographical memory in children with early thyroid hormone deficiency using a staged event

Autobiographical memory (AM) is a highly constructive cognitive process that often contains memory errors. No study has specifically examined AM accuracy in children with abnormal development of the hippocampus, a crucial brain region for AM retrieval. Thus, the present study investigated AM accuracy in 68 typically and atypically developing children using a staged autobiographical event, the Children's Autobiographical Interview, and structural magnetic resonance imaging. The atypically developing group consisted of 17 children (HYPO) exposed during gestation to insufficient maternal thyroid hormone (TH), a critical substrate for hippocampal development, and 25 children with congenital hypothyroidism (CH), who were compared to 26 controls. Groups differed significantly in the number of accurate episodic details recalled and proportion accuracy scores, with controls having more accurate recollections of the staged event than both TH-deficient groups. Total hippocampal volumes and anterior hippocampal volumes were positively correlated with proportion accuracy scores, but not total accurate episodic details, in HYPO and CH. In addition, greater severity of TH deficiency predicted lower proportion accuracy scores in both HYPO and CH. Overall, these results indicate that children with early TH deficiency have deficits in AM accuracy and that the anterior hippocampus may play a particularly important role in accurate AM retrieval.     

Impairment of episodic and semantic autobiographical memory in patients with mild cognitive impairment and early Alzheimer's disease

Autobiographical memory includes the retrieval of personal semantic data and the remembrance of incident or episodic memories. In retrograde amnesias, it has been observed that recall of autobiographical memories of recent events is poorer than recall of remote memories. Alzheimer's disease (AD) may also be associated with a temporal gradient (TG) in memory decline, though studies have yielded inconsistent results on this point. They have also yielded inconsistent results on whether AD might differentially affect semantic and episodic remembrance. Here, we compared autobiographical memory of childhood, early adulthood, and recent life among healthy control (HC) subjects, patients with early AD, and patients with amnesic mild cognitive impairment (aMCI). Both the aMCI and AD patients exhibited declines in recall of autobiographical incidents and semantic information. In AD patients, both components of autobiographical memory had a clear TG, with better preservation of memories of childhood than those of early adulthood and recent life. The TG of autobiographical memory decline in AD patients is more compatible with the Cortical Reallocation Theory than with the Multiple Trace Theory of memory consolidation. In contrast to AD patients, aMCI patients exhibited impaired recall of personal facts and autobiographical incidents relating only to recent life. The significant decline in autobiographical memory for recent life that occurred in aMCI patients suggests that deterioration of consolidation of personal facts and events begins with commencement of functional impairment in the hippocampus.     

Music evoked autobiographical memory after severe acquired brain injury: Preliminary findings from a case series

Music evoked autobiographical memories (MEAMs) have been characterised in the healthy population, but not, to date, in patients with acquired brain injury (ABI). Our aim was to investigate music compared with verbal evoked autobiographical memories. Five patients with severe ABI and matched controls completed the experimental music (MEAM) task (a written questionnaire) while listening to 50 “Number 1 Songs of the Year” (from 1960 to 2010). Patients also completed the Autobiographical Memory Interview (AMI) and a standard neuropsychological assessment. With the exception of Case 5, who reported no MEAMs and no autobiographical incidents on the AMI and who also had impaired pitch perception, the range of frequency and type of MEAMs in patients was broadly in keeping with their matched controls. The relative preservation of MEAMs in four cases was particularly noteworthy given their impaired verbal and/or visual anterograde memory, and in three cases, autobiographical memory impairment. The majority of MEAMs in both cases and matched controls were of a person/people or a period of life. In three patients music was more efficient at evoking autobiographical memories than the AMI verbal prompts. This is the first study of MEAMs after ABI. The findings suggest that music is an effective stimulus for eliciting autobiographical memories, and may be beneficial in the rehabilitation of autobiographical amnesia, but only in patients without a fundamental deficit in autobiographical recall memory and intact pitch perception.     

Hippocampal volume reduction and autobiographical memory deficits in chronic schizophrenia

Although autobiographical memory (AM) deficits and hippocampal changes are frequently found in schizophrenia, their actual association remained yet to be established. AM performance and hippocampal volume were examined in 33 older, chronic schizophrenic patients and 21 healthy volunteers matched for age, gender and education. Psychopathological symptoms and additional neuropsychological parameters were assessed by using appropriate rating scales; magnetic resonance imaging (MRI) 3-T data were analyzed via an automated region-of-interest procedure. When compared with the control subjects, patients showed significantly decreased left anterior and posterior hippocampal volumes. Episodic but not semantic AM performance was significantly lower in the patients than in the healthy controls. Both episodic and semantic AM deficits were significantly correlated with volume of the left hippocampus in the patient group. In contrast, deficits in verbal memory, working memory and remote semantic memory observed in the patients did not relate to hippocampal volume. Our findings indicate that AM deficits in chronic schizophrenia are associated with hippocampal volume reductions and underline the importance of this pathology in schizophrenia.     

Heroin abuse, autobiographical memory and depression

The early psychiatric interviews with opiate addicts are characterized by three features: 1) the patient has a very factual and objective conversation, 2) the evaluation of the autobiographical memory is very difficult, 3) there is a high prevalence of affective disorders responsible for an impairment in cognitive functions. Therefore we have two aims: First, to compare episodic and semantic autobiographical memory in opiate addicts and healthy controls. Autobiographical memory is the knowledge a person has about oneself and his past. Personal semantic memory is the knowledge of the biographical facts, general knowledge and beliefs about oneself. Autobiographical episodic memory concerns recollections of personal events clearly delineated in time and space. Second, to estimate the impact of depression on the ability to produce autobiographical recollection in a population of opiatre addicts. Participants were consecutive attenders of a methadone outpatient clinic who are multiple drug dependent patients consuming mainly heroine. The first investigation took place in entry and after two months. We have recruited 21 patients with a mean duration of intoxication of 11 years. Ten of these patients have been investigated again after 2 months and 8 of them have been included in a methadone maintenance program. The patients'investigation comprised two parts: first, the evaluation of autobiographical memory (only assessed at entry of the study) with an autobiographical fluency test and the semi-structured autobiographical memory interview of Kopelman; second, the psychiatric assessment included self-rating questionnaires and observer-rating questionnaires. Opiate addicts showed a decrease in episodic autobiographical memory but an increase in semantic affective memory and objective modalization. In the fluency test, there was no difference in the number of evoked items between opiate addicts and healthy controls. The educational level influences several results. The possible explanations of these results are the action of the toxic products and a particular psychic functioning. The lack of correlation between autobiographical memory and affective disorder suggests the implication of the drugs in the emergence of memory deficits. The improvement of depressive symptomatology after two months occurring without psychotropic drugs suggests the transient feature of depression and emphasises on non-pharmacological aspects of treatment.     

Alteration of autobiographical memory in amnestic mild cognitive impairment

The concept of amnestic mild cognitive impairment (aMCI) concerns a population of older individuals at high risk of developing probable Alzheimer's disease. Although anterograde memory deficits have been largely documented in patients with aMCI, little is known about the integrity of their autobiographical memory (AuM). This study aimed at evaluating AuM in aMCI individuals and at investigating whether their ability to retrieve AuMs varied as a function of whether the tests used required recognition or effortful retrieval processes. Fourteen aMCI patients and 14 matched controls underwent a standard neuropsychological evaluation and an extensive autobiographical assessment. AuM was explored using verbal material, the Autobiographical Memory Interview, and a visual task of personal photographs. Together, these tests tapped the semantic and episodic components of AuM and different cognitive processes involved in retrieval (recall and recognition). Results indicate that AuM is altered in aMCI patients. This impairment affects both episodic and semantic components of AuM, and is characterized by a general difficulty in recollecting personal episodes covering the entire lifespan, along with a loss of recognition of recently experienced episodes. Furthermore, recollection of personal episodes was correlated with scores on tests requiring retrieval abilities, while recognition of familiar photographs was correlated with scores on tests assessing encoding/storage of new information. Results suggest that the AuM deficit in aMCI patients may result from the combination of two mechanisms, an anterograde memory impairment impeding the storage of newly experienced events, and a global alteration of recollection affecting the recall of AuM covering all periods of life. Alteration of these processes may possibly be related to the progression and distribution of the neuropathological lesions in medial temporal and frontal lobe structures found in Alzheimer's disease.     

Prefrontal activity and impaired memory encoding strategies in schizophrenia

Schizophrenia patients have significant memory difficulties that have far-reaching implications in their daily life. These impairments are partly attributed to an inability to self-initiate effective memory encoding strategies, but its core neurobiological correlates remain unknown. The current study addresses this critical gap in our knowledge of episodic memory impairments in schizophrenia. Schizophrenia patients (n = 35) and healthy controls (n = 23) underwent a Semantic Encoding Memory Task (SEMT) during an fMRI scan. Brain activity was examined for conditions where participants were a) prompted to use semantic encoding strategies, or b) not prompted but required to self-initiate such strategies. When prompted to use semantic encoding strategies, schizophrenia patients exhibited similar recognition performance and brain activity as healthy controls. However, when required to self-initiate these strategies, patients had significant reduced recognition performance and brain activity in the left dorsolateral prefrontal cortex, as well as in the left temporal gyrus, left superior parietal lobule, and cerebellum. When patients were divided based on performance on the SEMT, the subgroup with more severe deficits in self-initiation also showed greater reduction in left dorsolateral prefrontal activity. These results suggest that impaired self-initiation of elaborative encoding strategies is a driving feature of memory deficits in schizophrenia. We also identified the neural correlates of impaired self-initiation of semantic encoding strategies, in which a failure to activate the left dorsolateral prefrontal cortex plays a key role. These findings provide important new targets in the development of novel treatments aiming to improve memory and ultimately patients' outcome.     

Autobiographical memory in progressive supranuclear palsy

Background: We aimed to investigate recall of autobiographical memories across lifetime periods in patients with progressive supranuclear palsy (PSP). Method: Patients with PSP (n = 10) were given a test of autobiographical and personal semantic information and the Addenbrooke’s Cognitive Examination (ACE). The result was compared to 30 matched neurologically intact participants. Result: A mild autobiographical memory impairment was observed in PSP without a temporal gradient for the recall of autobiographical or personal semantic information. Performance correlated with verbal fluency in ACE. Conclusion: Patients with PSP show mild deficits in autobiographical memory, which is likely to reflect a frontal retrieval deficit.     

Autobiographical memory deficits in Alzheimer's disease

Autobiographical memory comprises memories of one's own past that are characterized by a sense of subjective time and autonoetic awareness. Although autobiographical memory deficits are among the major complaints of patients with dementia, they have rarely been systematically assessed in mild cognitive impairment and Alzheimer's disease. We therefore investigated semantic and episodic aspects of autobiographical memory for remote and recent life periods in a sample of 239 nursing home residents (165 in different stages of Alzheimer's disease, 33 with mild cognitive impairment, and 41 cognitively unimpaired) with respect to potential confounders. Episodic autobiographical memories, especially the richness of details, were impaired early in the course of Alzheimer's disease or even in the preclinical phase, while semantic memories were spared until moderate stages, indicating a dissociation between both memory systems. The examination of autobiographic memory loss can facilitate the clinical diagnosis of Alzheimer's disease.     

Oxytocin and enhancement of the positive valence of social affiliation memories: An autobiographical memory study

Intranasal oxytocin has been shown to alter self-perceptions of personality (e.g., more trusting, increased extraversion). To follow up these findings, we examined the acute effects of two doses of intranasal oxytocin (24 IU and 48 IU) on another form of self-referential cognition: autobiographical memory. Changes in autobiographical memory (personal memories for the past) could conceivably effect change in self-perception and consequently alter social behaviors. We predicted that oxytocin would increase the number of specific personal memories recalled, and promote the recall of positive social affiliation memories. Seventeen male participants self-administered a placebo or oxytocin (24 IU, 48 IU) using a nasal spray on three separate occasions in a placebo-controlled, double-blind, and within-subject experiment. Participants completed the Autobiographical Memory Test (AMT) 110 minutes later. Analyses revealed a quadratic dose–response curve for the effects of intranasal oxytocin on autobiographical memory recall. The 24 IU dose, relative to the 48 IU dose and placebo, increased the number of specific personal memories recalled and promoted the recall of social affiliation memories that were rated more positively. The lack of effect with the 48 IU dose could be due to saturation of the oxytocin receptors at higher doses. Changes in autobiographical memory may be one mechanism by which oxytocin alters prosocial worldviews.     

Remote episodic memory deficits in patients with unilateral temporal lobe epilepsy and excisions.

The nature of remote memory impairment in patients with medial temporal lobe damage is the subject of some debate. While some investigators have found that retrograde amnesia in such patients is temporally graded, with relative sparing of remote memories (Squire and Alvarez, 1995), others contend that impairment is of very long duration and that remote memories are not necessarily spared (Sanders and Warrington, 1971; Nadel and Moscovitch, 1997). In this study, remote memory was assessed in 25 patients with unilateral temporal lobe epilepsy and 22 non-neurologically impaired controls using the Autobiographical Memory Interview (Kopelman et al., 1989). Results indicate that patients have impaired personal episodic memory but intact personal semantic memory. The impairment extends even to the most remote time periods in early childhood, long before seizure onset in many patients. As well, patients awaiting temporal lobectomy for control of seizures perform as poorly as those who have already undergone resective surgery. These results support the hypothesis that temporal lobe damage or dysfunction, caused by recurrent seizures or surgical excision, results in extensive retrograde amnesia for personal episodic memories. Interestingly, patients with radiological evidence of hippocampal sclerosis were not significantly more impaired than those without obvious sclerosis. These results indicate that even minimal damage to medial temporal lobes results in significant impairment to autobiographical episodic memory. These findings are more compatible with a memory loss or retrieval deficit rather than a consolidation account of remote memory impairment.     

Autobiographical memory in advanced multiple sclerosis: assessment of episodic and personal semantic memory across three time spans.

In order to investigate the status of remote memory the Autobiographical Memory Interview (AMI) was administered to 30 individuals with advanced multiple sclerosis (MS). In contrast to earlier studies which have shown only mild deficits in autobiographical memory in those with less physical progression of the disease, about two-thirds (60%) of the present MS sample had a deficit in autobiographical memory. The presence of such a deficit was not related to age, age of onset, duration of illness, or level of physical disability, but was related to level of general cognitive ability. Memory for episodic autobiographical incidents was more affected than for personal semantic information; a temporal gradient typical of some dementing conditions but not before demonstrated in MS, was also observed with memory for more recent events showing a significant decline.